Blank feeding mechanism for envelope forming machine



BLANK FEEDING MECHANISM FOR ENVELOPE FORMING. MACHINE Filed Sept. 15,1967 Feb. 10, 19 70 c. RICHARDS 2 Sheets-Sheet 1 INVENTOR; ROBERT C-RICHARDS BY fizmkwz 5 7%- monnevs Feb. 10,1970 RC. RlCHAl RDS 3,494,511

BLANK FEEDING MECHANISM FOR ENVELOPE FORMING MACHINE Filed Sept. 15,1967 v 2 Sheets-Sheet a United States Patent 3,494,611 BLANK FEEDINGMECHANISM FOR ENVELOPE FORMING MACHINE Robert C. Richards, Whitman,Mass., assignor to United States Envelope Company, Springfield, Mass., acorporation of Maine Filed Sept. 15, 1967, Ser. No. 667,896 Int. Cl.B65h /10, 3/08 US. Cl. 271-29 12 Claims ABSTRACT OF THE DISCLOSURE Astack of precut envelope blanks is supported in an inclined positionwith their forward ends uppermost. A vacuum roll, having internal vacuummeans for supplying vacuum to a given portion of its circumferentialsurface, supports the stack at a point spaced some distance from itsforward end and a dagger reciprocates between an active position whereinit supports the forward end of the stack, and an inactive position,wherein it is free of the stack, in timed relationship with movement ofa pivotally mounted vacuum probe. The probe has a concave face withvacuum ports which when brought into engagement with the bottom blank ofthe stack forms a dimple in such blank to provide a small pocket betweenit and the adjacent blank. As the probe approaches the bottom blank thedagger is withdrawn, so that the probe momentarily supports the forwardend of the stack, and is then returned into the pocket formed by theprobe so as to be inserted between the bottom blank and the nextadjacent blank. As the probe moves away from the stack in its returnmotion it bends the forward end portion of the lowermost blankdownwardly away from the adjacent blank and a pair of counter-rotatingcam segments enter the space provided between the deflected portion andthe adjacent blank to urge the stack upwardly and to urge the deflectedforward end portion of the lowermost blank downwardly onto the vacuumroll.

- SUMMARY OF THE INVENTION This invention relates to envelope formingmachines, and deals more particularly with a mechanism for successivelystripping flexible blanks from a stack of like blanks, and depositingthe blanks onto a rotating vacuum roll of the machine.

' The general object of the present invention is to provide a blankfeedingmechanism wherein the blanks are successively fed from the bottomof an inclined stack, in accurately indexed relationship with respect toa rotating vacuum roll around which each blank is fed as it enters themachine.

The drawings show a preferred embodiment of the invention and suchembodiment will be described, but it will be understood thatvariouschanges may be made from the construction disclosed, and that thedrawings and description are not to be construed as defining or limitingthe scope of the invention, the claims forming a part of thisspecification being relied upon for that purpose.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational vview ofa blank feeding mechanism embodying the present invention and includingapair of vacuum rolls between which each envelope blank is fed afterbeing stripped from a stack of such envelope blanks.

FIG. 2 is a vertical sectional view taken through the blank feedingmechanism of FIG. 1.

3,494,611 Patented Feb. 10, 1970 ICC FIG. 3 is a sectional view takenalong the line 33 of FIG. 2.

FIG. 4 is a vertical sectional view similar to FIG. 2 showing themechanism at approximately ninety degrees later in its cycle ofoperation.

FIG. 5 is a vertical sectional view similar to FIGS. 2 and 4 showing themechanism at approximately ninety degrees (90) later in its cycle ofoperation from the showing of FIG. 4.

FIG. 6 is a sectional View taken on line 66 of FIG. 2.

DETAILED DESCRIPTION OF THE DRAWINGS Turning now to the drawings ingreater detail, FIG. 1 shows a blank feeding mechanism 10 embodying thein vention for use in feeding envelope blanks to an envelope formingmachine (not shown). A shaft 12 is driven from the envelope formingmachine and carries a pulley 14 around which is entrained a timing belt16 which rotates a vacuum roll 18 on a fixed shaft 20. The shaft 20 ispreferably hollow and used as a tube for supplying vacuum to the roll18. The vacuum roll 18 is drivingly connected to a second vacuum roll 22which is similarly supported so that the envelope blank to be fed intothe envelope forming machine passes clockwise around the upper surfaceof the roll 18, thence between the rolls 18 and 22, and counterclockwisearound the underside of the second vacuum roll 22, as indicated by thearrow 24. Each of the vacuum rolls 18 and 22 rotates on its associatedvacuum supply tube which communicates with vacuum ports, such as shownat 23, 23 in FIG. 2, distributed over a given portion of thecircumferential surface thereof, the vacuum ports of the two rolls beingrelated to one another and supplied with vacuum during given portions ofeach revolution of each roll for feeding the envelope blankstherebetween in a well known manner.

Means are provided for supporting a plurality of precut envelope blanks25, 25 in an inclined stack, as indicated generally at 26, with theirforward ends uppermost. Preferably, and as shown in FIG. 1, such meanscomprises a pair of side posts, one of which is shown at 28, a bottompost or stop 29 and a plate or other means which provides a generallysmooth fiat surface 31 against which the vertically lower portion of thelowermost blank of the stack rests. The vacuum roll 18 also supports orengages part of the stack during a portion of each cycle of operationand is located between the upper end of the supporting surface 31 andthe upper or forward end of the stack with its circumferenceapproximately tangent to the surface 31. As shown by the dash-dot linesof FIG. 3, the illustrated feeding mechanism is used for feedingenvelope blanks, such as shown at 25, having generally triangularlyshaped forward end portions but, although, a blank with a generaltriangularly shaped forward end portion is shown in FIG. 3, it will beapparent that other shapes of blanks may as well be used with thefeeding mechanism of this present invention.

In accordance with the present invention, a cross shaft 30 is rotatablysupported above the vacuum roll 18, and is drivingly connected theretoby a second timing belt 32. The cross shaft 30 is parallel to the axisof rotation of the vacuum roll 18 and rotates in timed relationshiptherewith. It also carries an eccentric pin 34 which rotates in a slot36 provided for this purpose in a crank arm 38. The crank arm 38 ispivotally supported for movement about a fixed axis, defined by a pivotpin 40, in response to the rotation of the shaft 30 and eccentric pin34. The crank arm 38 carries a vacuum probe 42 which moves arcuatelyfrom an inactive or retracted position, such as shown in full lines inFIG. 1, toward the position of FIG. 2 wherein its forward face 43, whichincludes vacuum 3 I ports 45, 45, engages the lowermost blank. When theprobe 42 reverses direction, as shown in FIG. 4, it pulls with it theleading or upper end portion of the lowermost alank and deflects it intothe shape there depicted. It should also be noted, as shown best in FIG.6, that the forward face 43 of the probe 42 is concave and when it:ontacts the lowermost blank 25 the vacuum applied to the blank by theprobe deforms the blank to the shape of the face 43 to form a smallpocket 47 between the lowermost blank and the next adjacent blank ofsuflicient size to loosely accommodate a dagger 48- which moves Lnto thepocket shortly after it is formed.

In further accordance with the present invention, the lagger 48 ismounted for reciprocable motion between be solid and broken linepositions of FIG. 2, toward and away from the upper edge of the stack toenter the pocket 17 formed by the probe between the lowermost blank andhe next adjacent blank and to thereafter maintain the ;tack in positionwhile the probe moves from its position )f FIG. 2 to the position ofFIG. 4. Preferably, and as Jest shown in FIG. 2, the dagger 48 ismounted at the free end of a lever 50, which lever is pivotally mountedit its opposite end for movement about a fixed axis deined by a pivotpin 52. Means is provided for moving he dagger 48 in timed relationshipwith the probe 42 that each operates sequentially on the lowermostblank. Ihis timing is such that the dagger 48 is withdrawn from :hestack shortly before the probe engages the stack. Then after the probeengages the lowermost blank and forms :he pocket 47 the dagger is movedinto the pocket before :he probe is moved away from the stack. Thedagger 48 remains in this latter position until just prior to thebeginning of the succeeding cycle of operation when it is ifted from thestack to allow the vacuum probe 42 to :ngage another blank and formanother pocket.

Turning now to a more detailed description of the neans for moving thedagger carrying lever 50, spring aiasing means indicated generally at 54is provided for irging the lever 50 to the position shown in FIG. 2. Camneans is provided for momentarily raising the lever 50, and with it thedagger 48, to an inactive position for pernitting the probe 42 to engagea succeeding lowermost Jlank inthe stack. As shown in FIG. 2, said meansfor 'aising the lever 50 comprises a rotating cam 56 carried my asecondary cross shaft 58 geared to the upper cross :haft 30 by themeshing spur gears 60 and 62 respectively best shown in FIG. 3). The cam56 in turn cooperates vith a sliding pin 59 pivotally connected at itslower end 0 the arm 50 and having a notch so arranged that during :achrevolution of the cam 56 its finger enters the notch llld lifts the pin59.

The present invention also provides means which is nsertable between thestack 26 and the downwardly delected forward end portion of thelowermost blank. The aid means supports and raises slightly the forwardend If the stack, to aid in separating the lowermost blank rom thestack, and further deflects the forward blank )ortion toward the vacuumroll 18, all in timed relation vith the operation of the dagger 48 andthe vacuum probe l2. As best shown in FIG. 3, the above-mentioned means:omprises a pair of counter-rotating segmented cams 64 ind 66 each ofwhich is continuously driven in the direcion of the arrows associatedtherewith by gears 68 and '0' respectively mounted on the shaft 58. Eachof the ams 64 and 66 is carried on a stub shaft, which shafts ,l'socarry a pair of gears for meshing with said gears i8 and 70respectively.

Referring now to FIG. 4, and more particularly con ider'ing the actionof the counter-rotating cams 64 and' F6, it will be noted that theleading edge 72 of the cam i6 is so arranged that after the forwardportion of the dwermost blank is withdrawn or bent from the stack andnoved to approximately the position shown in FIG. 4, Iythe vacuum probe42, the leading edge portion of the am enters the space so formedbetween the stack and 3,494, 11 r f f the blank. The edge 72 is furtherarranged so as to b in the same plane as, or slightly below the planeof, the dagger 48 so that as the edge approaches the stack it will movebelow the blank being held by the dagger 48. Immediately behind the edge72, the cam 66 includes an inclined surface 73 facing thestack 26 whichleads from the edge 72 to another generally flat surface 75 concentricwith the axis of the cam, facing the stack 26, and having an angularextent of approximately 180. This surface 75 is located above theplaneofthe dagger 48 so that when it is moved into engagement with thebottom of the stack, by rotation of the cam 66, it lifts up the stackand, therefore, aids in separating the stack from the blank being fed.This is of particular advantage in cases where the blanks are die cut assuch blanks often have interlocking fibers which resist the pulling ofthe bottommost blank from the stack in a plane parallel to the stackbottom. The lifting of the stack by the cam surface 75 separates atleast some of such interlocking fibers and makes the withdrawal of thebottommost blank easier. Although FIGS. 2, 4 and 5 show only the cam 66,it should be understood that the cam 64 is a mirror image duplicate ofthe cam 66 and includes an inclined surface similar to the inclinedsurface 73 and a flat arcuate surface similar to the surface 75. In FIG.3 this latter surface is shown at 77 on the cam 64. FIG. 5 shows the cam66 rotated approximately ninety degrees from the position shown in FIG.4. In this position the upper flat surface 75 engages and lifts theforward end of the stack as above described, and from this figure itwill be noted that the cam also includes, below the surface 75, asurface.79 which, when the cam is in the illustrated angular position, islocated close to the circumference of the vacuum roll 18 and serves topositively separate the withdrawn blank from the vacuum probe 42 and todeflect it toward and to hold f it onto the vacuum roll 18. The surface,79 as. viewed in the horizontal section of FIG. 5 has a concavecurvature generally conforming to the curvature of the circumference ofthe roll 18 and is concentric with the axis of the'cam 66. Again, itshould be understood that the cam 64 also includes a surface similar tothe'surface"7 9 of, the cam 66 for deflecting the withdrawnblank towardthe vacuum roll 18.

The vacuum roll 18 is moved in timed relationship with,

the movement of the probe 42, cam 66 and dagger 48 and this timing issuch that the vacuum. ports 23, 23 of the roll are presented to theforward end portion of the lowermost blank as it is moved from the stackby the probe 42 to the position of FIGJ 4. Also, at this time vacuum isapplied to the ports 23, 23 so that the roll grasps the blank and pullsit from the stack. After the forward portion of the blank reaches thesecond vacuum roll 22 vacuum is applied to similar vacuum'ports in theroll 22, and the vacuum at its ports 23, 23 is turned off, so that theblank is transferred to the roll 22 and the re maining portion of theblank is pulled from the stack as a result of the blank passing throughthe nip of the two rolls 18 and 22.

After the trailing ends of each of the counter-rotating segmented cams64 and 66 have been rotated to substan tially the positions shown inFIG; 3, the mechanism de scribed hereinabove will-have been repositionedfor an other cycle of operation, so as to strip a succeedingflowermanner described hereinabove.

I claim:

1. An apparatus for feeding blanks individually from a stack of likeblanks, said apparatus comprising means for supporting a stack ofsuchblanks', cyclically operable means for partiallyseparating' theforward portion of the lowermost blank in said stack from the nextadjacent blank by bending said lowermost blank away from said stack, andmeans for grasping said forward end portion of said lowermost blankwhile said stack is displaced by said second means and for pulling saidlowermost blank from said stack, a pair of cooperating segmentedrotating members each having a cam surface on one side for displacingsaid stack from its normal position and a cam surface on the oppositeside for deflecting said separated forward portion of said lowermostblank away from said stack.

'2. An apparatus for feeding blanks individually from a stack of likeblanks as defined in claim 1 further characterized by said means forseparating the forward portion of said lowermost blank from the nextadjacent blank of said stack comprising a vacuum probe cyclicallymovable toward and away from the under-surface of said lowermost blank,said probe having a concave face for engagement with said undersurfaceso that when said probe is brought into engagement with said lowermostblank it deforms said lowermost blank to form a pocket between saidlowermost blank and the next adjacent blank, and a cyclically movabledagger operable adjacent the forward end of said stack which dagger ismovable into said pocket after it is formed by said probe to restrainsaid next adjacent blank from moving with said lowermost blank as saidlowermost blank is bent away from said next adjacent blank by saidprobe.

3. An apparatus for successively stripping flexible blanks from a stackof like blanks each of which has a forward end portion, said apparatuscomprising support means for the blanks in said stack and including arotatably mounted vacuum roll below the forward end portion of thelowermost blank, means including a vaccum probe mounted for cyclicalmotion toward and away from the underside of the forward end portion ofsaid lowermost blank for partially deflecting said forward end portionaway from said stack and downwardly toward said vacuum roll, and a pairof cooperating segmented cams, each cam having an upper surface forpushing the stack upwardly and a lower surface for deflecting theforward blank portion away from the stack.

4. Apparatus according to claim 3 further characterized by said vacuumprobe having a concave face so as to form a pocket between saidlowermost blank and the next adjacent blank when said probe is movedinto engagement with said lowermost blank, a dagger movable relative tosaid stack, and means for moving said dagger in times relation to themovement of said vacuum probe, said dagger and said means for moving itbeing so arranged that said dagger is withdrawn from said stack as saidprobe approaches said lowermost blank and is then moved into said pocketto support the forward end of said stack and prevent the next adjacentblank from moving with said lowermost blank as said lowermost blank isdeflected by said probe.

5. Apparatus according to claim 4 and further characterized in that saidvacuum roll is continuously rotated about an axis perpendicular to thedirection of movement acterized in that said cams are mounted forrotation in opposite directions about axes generally perpendicular tosaid stack, and said cams being driven from said cross shaft so as torotate in timed relationship with said dagger and probe.

8. Apparatus according to claim 3 and further characterized in that saidstack support means holds said blanks at an angle to the horizontal withthe forward ends uppermost, said probe being so mounted on said crankarm as to move substantially tangentially with re spect to said vacuumroll toward and away from the underside of said lowermost blank betweensaid counterrotating segmented cams, said vacuum roll having vacuumports on a given angular portion of its circumferential surface whichangular portion is so arranged as to be presented to the forward endportion of each blank after it has been partially deflected by saidprobe.

9. An apparatus for feeding blanks individually from a stack of likeblanks each of which has a forward end portion, said apparatuscomprising support means for v the blanks and including a rotatablymounted vacuum roll of said stripped blank, a cross shaft driven fromsaid having ports on a given angular portion of its circumferentialsurface, a vacuum probe mounted for pivotal movement toward and awayfrom the underside of the forward end portion of the lowermost blank forpartially deflecting said forward end portion away from said stack anddownwardly toward said vacuum roll, said probe having a concave face soas to form a pocket between said lowermost blank and the next adjacentblank when said probe is moved into engagement with said lowermostblank, a dagger movable in timed relationship with said probe to enterthe pocket and prevent the adjacent blank from moving with the lowermostblank as the latter is deflected by said probe, and cam means insertablebetween said stack and the forward portion of said lowermost blank afterthe blank has been partially deflected for supporting the stack andfurther deflecting the lowermost blank toward said vacuum roll.

10. Apparatus according to claim 9 further character ized in that saidcam means comprises a pair of segmented rotating cam members arranged oneither side of said pivotally mounted probe, said cam members havingcooperating upper cam surfaces for raising said stack slightly andcooperating lower cam surfaces for wrapping said blank around a portionof said vacuum roll.

11. Apparatus according to claim 10 further characterized in that saidvacuum probe moves substantially tangentially with respect to saidvacuum roll toward and away from the underside of said lowermost blankbetween said rotating cam members, said members rotating in oppositedirections and in timed relationship with said probe and with saidangular portion of said vacuum roll.

12. Apparatus according to claim 11 further characterized in that saidcounter-rotating cam members have lower cam surfaces which are concavein contour and conform generally to the curvature of said vacuum rolland which lower concave cam surfaces pass in close proximity to thecircumference of said vacuum roll during each revolution for Wrappingthe blank around a portion of said roll other than the said angularportion thereof.

References Cited UNITED STATES PATENTS 2,849,232 8/ 1958 Halahan 271292,954,225 9/1960 Novick 27129 3,394,930 6/ 1968 Guggisberk 27129 RICHARDE. AEGERTER, Primary Examiner

